Hi, narkidarki
I use next defending corner tactic in 4-2-3-1:
DR and DL - man mark
DCL and DCR - mark tall player
2 Centre Mid (MC or DMC)- man mark (need all-round mid with good marking and tackling)
CF and AMC - stay forward (or 2 CF stay forward)
Winger Left - mark near post
Winger Right...